Well cementing apparatus



C. E. BURT WELL CEMENTING APPARATUS septu 29, 1949.

Filed oct. 25, 1944 INVENTCR. 5a/87;

(9i/w Q. ATTORNEY.

Patented Sept. 20, 1949 Y I WELL CEMENTING ArPARA'rUs A:Clarence E.` Burt,l Pasadena; Calif., assignor to Baker Oil Tools, Inc., Vernon, Calif., a

" tion jof ,California Y Applicationoctober-zs, 1944, serial No. 560,283

'I'his invent-ion relates to wel1=cementing apparatus adapted toform part of va casingstring. Apparatus for cementing well casing at-one or l i` claims. (ci. 16641) more points above the lower end of the casingr Y.

string embody side ports through which the cementitious material can be ejected from the casing for passage into the annulus between the casing and wall of the wellbo re A back pressure valve may :be provided on theexterior of the casing to close the ports and-prevent return ow of the cementitious material Ainto the leasing. Under lsome conditions of -operation, itis also desired torconne the cementitious .material deposited behind the leasing to a particular location along cerned with-thecontrol voit -back pressure valves en in apparatus ofthe character indicated; and another phase ofthe invention-is .directed to'controlling such valves in conjunction with the control of annular casing barriers or bridges.

More specifically, it is. an object of the present invention to provide a ported well casing apparatus embodying an external backpressure valve protected against damage -while the well casing'is run in the well bore 'by-a device-which also serves to hold an annular casing bridge or barrier infretracted positionY until thelatter isvto be released. l

Another object Voitheinvention is to provide an improved side ported wellgcasing apparatus to the pressure of iluid within the apparatus,

lwhich is prevented froml allowing passage of fluid from within the casing *by a device whichalso Vserves -to -hold an annular casing bridge or barrier in retracted position until the latteris to be released. Y Y

A'further object of the invention isl to provide Sian improved side ported well casing apparatus having .an external back pressurevalve subject to the pressure of fluid Awithin theapparatus; but I; -which vis prevented from allowing: fluidy to pass from withinj the casingthrough the port t-o the exterior until a predetermined pressure is Vbuilt up within the casing, thereby allowingfluid ata -having an external 'backvpressure valve subject, z

lower pressure to be pumped throughthe casing.,

toa pointbelow the port.- .f

Still another object of th e i nvention is lto provide a protective Ydevice-arou-nda back pressure rvalve on .the exterior O f a well casing apparatus Y which is n lovablefromv itsfprotective, positionwhen the back pressure valve is to function.

- Yet another object of .the invention` is tov provide an apparatus useful in Vthe multiple stage or yseries .cernenting of` well "bores embodying a retainer device on the exteriorfofthe vcasing lfor preventing flow from .withiny the ycasing to its exterior until a predetermined pressure ishuilt up, allowing oementitious material to first ejected fromthe casingl at Va lower point.

A further object of the invention -is t0 provide a well casing apparatus embodying an extern-al back pressure valve cooperable with an external retainer in such' manner as to prevent flowv of fluid within the ycasing to itsV exterior untilV a predetermined hydraulic pressure is imposed on the combination 'from within the casingf This inventionhas other objects that will becomeapparent from a consideration of the embodiment shown in the Vdrawings accompanying and forming` part of the present specication. This form will now be described in detail, butA it is -to be understood thatsuchjdetailed description is not to be taken in alimited sense, since the scope' of thein'vention best defined 'by the claims appended hereto. l

Referring to the drawings: Y Figure 1 is a longitudinal section and elevation of a'well casing, illustrating therapparatus in one posi-tion offoperation; n

Figure 2 is a view similar to Figure 1`, illustrating the apparatus Vin another position of 'operation;

Figure Bissau enlarged View of part of theaplparatus shown in Figure 1; and

Figure 4V isv an enlarged. view of part of the, `paratus shown in Figure 2.

As disclosed in the drawings',the apparatus includes a tubular nipple or collar I0 adapted -to alp- "form part of a casing string'by being connected to adjacent casing sections II, I2. vThe collar is provided with a plurality Vof circumferentially Vspaced .sideports I3 forV establishing communication between its interior and exterior. A back the ports in Vsuch manner as to permit outward passage of iluid from the interior vof the casing,

A.and to Vprevent its return flow into' the casing. In the specific example shown, such b-ackpressure valve takesthe form of anelasticf rubber or similarV sleeve I4, having one end` anchored to the Acollar I0 by a collarl rib I5 fitted 4within a com- --panion groove in the sleeve I4. end may also be held securely to the collar by an encompassing strap I6, firmly .clamping an innersleeve rib `I 1 55 into its companion Ygroove formed between the collar rib I5 an-d a lower `outwardly projecting collar ange I8.

The sleeve I4 tends to close inherently in van inward direction over the ports I3 to prevent fluid 'from passing back into the collar Il), but the pressure of the uid within the casing and its collar can flex the free end of the sleeve in lan outward direction to enable outward fluid passage from' the interior ofthe Collar to its exterior.

The back pressure valve I4 is initially held against outward flexure by a retainer I9 in the form of a rigid sleeve extending over the valve,

and having an upper head adapted'toslide. along the collar I0 above the free end of the elastic sleeve valve. The retainer I9 is held in this position by releasable means, such as one or more frangible shear screws 2| extending through the head 20 and threaded into the collar. Leakage between the head and collar is prevented by a side seal 22 in the head slidably sealing with the outer surface of the collar.

' The shear screws 2l have `a predetermined shear value and will'not disrupt until the lluid pressure in the casing exceeds a corresponding predetermined amount. Cement slurry and other fluids may be pumped down through the casing string and its collar for discharge at some point therebelow, as through a shoe (notshown) at the lower end of the casing string. Increase of the iiuid pressure within the casing to a predetermined amount will cause sufiicient iluid force Vto be exerted against the inner surface of the retainer head 20, after passing through the ports I3 and along the inner surfaceoi the flexible sleeve valve I4, to disrupt the shear screws 2I and elevate the retainer I9 sufficiently :until it is removed Vfrom contact with the rubber sleeve valve I4 (see Figure 2). The fluid can then'pass outwardly through the ports I3 and stretch, or otherwise flex,V the free end of the sleeve valve I4, in an outward direction to discharge intothe annulus around the casing. Decreasein the pressure of the rfluid will allow thevalve I4 to move back inherently to closed position over theports I3, being held in this position by the hydrostatic head of the heavier fluid, such as cement slurry, on theV exterior of the casing, which presses it lirmly against the ,collar I0 and holds it in leakproof relation over the ports.k

Sufficient pressure can be built up in the liuid within the collar I0, forming part of the casing, by any suitable means. In the example disclosed in the drawings, a seat 23 for a bridging element may be rigidly secured to the interior of the collar ID below the ports I3. This seat has a central passage 24 through which uid can pass for discharge at a point below the collar. Y When pressure is to be built up in the collar to the aforementioned predetermined value to shear the screws, a suitable ball 25 or other bridging member is dropped into the casing and allowed to gravitate to its companion seat 23, closing the central passage 24 and Venabling the fluid pressure in the Vcasing thereabove to be increased sufficiently to shear the screws ZI and elevate the retainer vI9 from engagement with Athe flexible sleeve valve I4.

It is to be noted that Huid under pressure is incapable of passing through the ports I3 and intol the annulus around the casing in one direction by the sealing action of the side seal 22 in the retainer head 20 against the external wall of the collar IU'and also by the engagement of the externalsurface of the sleeve valve I4 with 'the interior wall of the retainer sleeve I9.' Leak- 4 V age of this uid in the other direction is prevented by the lockingV of the lower end of the sleeve valve I4 to the collar I0 by the intertting ribs I5, I1, which may be supplemented by the 5 steel strap I6. The outwardly projecting flange I8 on the collar serves to support the secured end of the rubber sleeve valve I4 and also functions as a guide along which the retainer sleeve I9 may slide in shifting to its ineective position shown in Figure 2.

.In installations wherein the cementitious material is to be prevented from gravitating or othewise depositing below the collar, an annular barrier or bridge 26 is secured to the collar. Such barrier may assume various forms and is disclosed in the drawings as of the petal type, described in Patent No. 2,117,538. This barrier is inthe form of a basket when released and con- Sists o a plurality of leaf springs 21 secured to the exterior Vof overlapping basket petals 28, with the ends 21a of the springs welded or otherwise suitably attached to the collar. The springs 21v and petals 28 inherently tend to assume an expanded generally frusta-conical or basket shape. The basket is fastened to the collar with its attached petals and springs heldinitially in retracted position against the casing. As shown in the drawings, the retainer sleeve I9 extends beyond the collar flange I8 to encompass the free ends 2lb of the leaf springs and petals, holding them against the collar I0 and free from contact with the Wall of the well bore. When suiicient pressure is imparted to the fluid within the casing to shear the screws 2 I, the elevational? the retainer I9 to free the back pressure valve I4 also removes restraint from the free ends 2lb of the springs 21 and petals 28 to allow their inherent expansion outwardly into engagement with the'wall of the well bore, thus forming an annular barrier to the passage of iiuids in a downward direction, in the particular arrangement shown in the drawings.

Although the drawings specically illustrate an upright barrier or basket 26 to prevent the cementitious material or other fluids discharged through the ports I3 from moving downwardly below the basket, the arrangement can also be incorporated in the casing string in` an inverted position to prevent upward passage of iluids around the'casing beyond the point at which the expanded casing bridge or barrier might be located.

It is, accordingly, apparent that a well cementing apparatus has been provided in which a back pressure valve I4 `is protected against damage while the casing string is being lowered in the well bore by a device which cooperates with the valve to prevent outward owof fluid through the ports I3 to the exterior of the casing until desired. Such outward flow will only occur after a predetermined degree of pressure has been built up in the uid within the casing. In addition, the protective or retainer device I9 can also be used to hold a casing barrier 26 in retracted position while the casing is being run in the well bore and until such time as it is to perform its function, thereby preventing potential damage to the barrier structure, especially When used in an inverted position, whileY the casing is lowered through the bore hole. Moreover, the initial securing of the basket 26 in retracted position permits more ready circulation to take place along the entire casing string to condition the hole along its whole length preparatory to the cementing opera-tion. The arrangement `lends itself readily to multiple stage or series cementing operations by allowing iluid under pressure to be pumped past the side ports I3 for ejection from the casing string at a predetermined location below the ports, after which the ports may be opened to permit the flow of iiuid therethrough to the exterior of the casing.

I claim:

1. An apparatus including a ported tubular member adapted to form part of a well casing string, an elastic back pressure sleeve valve disposed over the member port and having one end secured to said tubular member and its other end movable to permit outward flow of iiuid from the interior of the member through said port to the exterior of said member, and a shiftable sleeve disposed over and engageable with said elastic sleeve valve in leakproof relation with respect thereto, said shiftable sleeve making slidable sealing engagement with the exterior of said member at said other end of said elastic sleeve valve.

2. An apparatus including a ported tubular member adapted to form part of a Well casing string, an elastic back pressure sleeve valve disposed over the member port and having its lower end secured to said tubular member and its upper end movable to permit outward flow of uid from the interior of the member through said port to the exterior of said member, and a shiftable sleeve valve disposed over and engageable with said elastic sleeve valve in leakproof relation with respect thereto, said shiftable sleeve valve making slidable sealing engagement with the exterior of said member above said elastic sleeve valve.

3. An apparatus including aV ported tubular member adapted to form part of a well casing string, an elastic back pressure sleeve valve disposed over the member port and having one end secured to said tubular member and its other end movable to permit outward now of iiuid from the interior of the member through said port to the exterior of said member, a well device mounted on said member for bridging the annular space between said member and the surrounding wall of a well bore, and a shiftable sleeve disposed over and engageable with said elastic sleeve valve in leakproof relation with respect thereto, said shiftable sleeve having one end disposed over said well device to hold the same in retracted position and its other end in slidable sealing engagement with the exterior of said member at said other end of said elastic sleeve valve.

4. An apparatus including a ported tubular member adapted to form part of a well casing string, an elastic back pressure sleeve valve disposed over the member port to permit outward iiow of uid from the interior of the member and to prevent inward flow of fluid through said port, a retainer sleeve slidable along the exterior of said member and disposed over and engaging the exterior of said elastic sleeve valve to prevent outward iiow of iiuid from the interior of the apparatus to its exterior, said retainer sleeve in its valve engaging position dening a sealed chamber with said member in communication with the interior of said member, whereby uid at a predetermined pressure within said member shifts said retainer sleeve along the exterior of said member and elastic sleeve valve to a position permitting such outward flow of such fluid.

5. An apparatus including a ported tubular member adapted to formipart of a casing string, a. back pressurevalve disposed over the member w port to permit outward flow of fluid from the interior of the member and to prevent inward flow of fluid through said port, a well device mounted on said member for bridging the annular space between said member and the surrounding wall of a well bore, shiftable means disposed over and engaging the back pressure valve and well device to prevent such outward flow of fluid and to hold said well device in retracted position, said shiftable means in its valve engaging position defining a sealed chamber with said member in communication with the interior of said member, whereby fluid at a predetermined pressure within said member shifts said shiftable means from engagement with said back pressure valve and well device, thereby allowing outward passage of uid from the interior of the apparatus to its exterior and expansion of said well device into engagement with the wall of said well bore.

6. An apparatus including a ported tubular member adapted to form part of a casing string, an elastic back pressure sleeve valve disposed over the member port to permit outward flow of iiuid from the interior of the member and to prevent inward flow of fluid through said port, a well device mounted on said member for bridging the annular space between said member and the surrounding wall of a well bore, a retainer sleeve slidable along the exterior of said member and disposed over and engaging the exterior of said elastic sleeve valve and said well device to prevent such outward ow of uid and to hold said well device in retracted position, said retainer sleeve in its valve engaging position deflning a sealed chamber with said member in communication with the interior of said member, whereby iiuid at a predetermined pressure within said member shifts said retainer sleeve along the exterior of said member, said elastic sleeve valve and said well device rto a position permitting the aforesaid outward flow of iluid and expansion of said well device into engagement with the wall of said well bore 7. An apparatus including a ported tubular member adapted to form part of a well casing string, a back pressure valve disposed over the member port to permit outward flow of fluid from the interior of the member and to prevent inward ilow of fluid through said port, hydraulically shiftable means slidable along the exterior of said member and disposed over and engaging the exterior of said valve to prevent outward flow of uid from the interior of the apparatus to its exterior, said hydraulically shiftable means in REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 2,275,937 Baker Mar. 10, 1942 2,330,267 VBurt et al Sept. 28, 1943 2,344,120 Baker Mar. 14, 1944 

